During the manufacture of flat panel displays, a glass substrate may be placed on a support stage for processing and/or testing purposes. Typical substrate processing may include lithography, deposition, etching, annealing, etc., and typical substrate testing may include verifying the operation of thin film transistors formed on the substrate, e-beam inspection, defect detection, etc.
To accurately identify device and/or substrate locations for processing and/or testing, and/or to reduce device/location search times, a position of a substrate relative to a support stage should be determined. Accordingly, improved methods and apparatus for quickly and accurately positioning a substrate relative to a support stage would be desirable.